Three solutions, all originally at 20°C, are combined in a calorimeter. The temperature of the reaction mixture is monitored, as show in the graph below. 34.0- 32.0 30.0 28.0- 26.0- 24.0 22.0- 20.0 18.0 Time Ms. Prohaska repeats the same experiment, but this time she doubles the volume of each reactant, but keeps the concentration the same as in trial one. The magnitude of the molar enthalpy change calculated from the results of a second experiment is the same as the result calculated from the first experiment. Explain this result.

Three solutions, all originally at 20°C, are combined in a calorimeter. The temperature of the reaction mixture is monitored, as show in the graph below. 34.0- 32.0 30.0 28.0- 26.0- 24.0 22.0- 20.0 18.0 Time Ms. Prohaska repeats the same experiment, but this time she doubles the volume of each reactant, but keeps the concentration the same as in trial one. The magnitude of the molar enthalpy change calculated from the results of a second experiment is the same as the result calculated from the first experiment. Explain this result.

Chemistry

9th Edition

ISBN:9781133611097

Author:Steven S. Zumdahl

Publisher:Steven S. Zumdahl

Chapter13: Chemical Equilibrium

Section: Chapter Questions

Problem 10RQ: The only stress (change) that also changes the value of K is a change in temperature. For an...

See similar textbooks

Similar questions

5.11. Determine the numerical value of Q for the reaction conditions indicated.
Indicate whether each statement below is true or false. If a statement is false, rewrite it to produce a closely related statement that is true. For a given reaction, the magnitude of the equilibrium constant is independent of temperature. If there is an increase in entropy and a decrease in enthalpy when reactants in their standard states are converted to products in their standard states, the equilibrium constant for the reaction must be negative. The equilibrium constant for the reverse of a reaction is the reciprocal of the equilibrium constant for the reaction itself. For the reaction H2O2(ℓ) ⇌ H2O(ℓ) + O2(g) the equilibrium constant is one half the magnitude of the equilibrium constant for the reaction 2H2O2(ℓ) ⇌ 2H2O(ℓ) + O2(g)
5.12. True or false: If all the partial pressures of reactants and products drop by half, the value of Q drops by half. Give an example of a chemical reaction to support your answer.
Describe a nonchemical system that is in equilibrium, and explain how the principles of equilibrium apply to the system.
A gaseous material XY(g) dissociates to some extent to produce X(g) and Y(g): XY(g)X(g)+Y(g) A 2.00-g sample of XY (molar mass = 165 g/mol) is placed in a container with a movable piston at 25C. The pressure is held constant at 0.967 atm. As XY begins to dissociate, the piston moves until 35.0 mole percent of the original XY has dissociated and then remains at a constant position. Assuming ideal behavior, calculate the density of the gas in the container after the piston has stopped moving, and determine the value of K for this reaction of 25C.
The following equilibrium is established in a closed container: C(s)+O2(g)CO2(g)H=393kJmol1 How does the equilibrium shift in response to each of the following stresses? (a) The quantity of solid carbon is increased. (b) A small quantity of water is added, and CO2 dissolves in it. (c) The system is cooled. (d) The volume of the container is increased.
Calculate rH for the reaction 2 C(s) + 3 H2(g) + O2(g) C2H5OH() given the information below. C(s) + O2(g) CO2(g) rH = 393.5 kJ/mol-rxn 2 H2(g) + O2(g) 2 H2O() rH = 571.6 kJ/mol-rxn C2H5OH() + 3 O2(g) 2 CO2(g) + 3 H2O() rH= 1367.5 kJ/mol-rxn
The only stress (change) that also changes the value of K is a change in temperature. For an exothermic reaction, how does the equilibrium position change as temperature increases, and what happens to the value of K? Answer the same questions for an endothermic reaction. If the value of K increases with a decrease in temperature, is the reaction exothermic or endothermic? Explain.
When a mixture of hydrogen and bromine is maintained at normal atmospheric pressure and heated above 200. °C in a closed container, the hydrogen and bromine react to form hydrogen bromide and a gas-phase equilibrium is established. Write a balanced chemical equation for the equilibrium reaction. Use bond enthalpies from Table 6.2 ( Sec. 6-6b) to estimate the enthalpy change for the reaction. Based on your answers to parts (a) and (b), which is more important in determining the position of this equilibrium, the entropy effect or the energy effect? In which direction will the equilibrium shift as the temperature increases above 200. °C? Explain. Suppose that the pressure were increased to triple its initial value. In which direction would the equilibrium shift? Why is the equilibrium not established at room temperature?
Substances that poison a catalyst pose a major concern for many engineering designs, including those for catalytic converters. One design option is to add materials that react with potential poisons before they reach the catalyst. Among the commonly encountered catalyst poisons are silicon and phosphorus, which typically form phosphate or silicate ions in the oxidizing environment of an engine. Group 2 elements are added to the catalyst to react with these contaminants before they reach the working portion of the catalytic converter. If estimates show that a catalytic converter will be exposed to 625 g of silicon during its lifetime, what mass of beryllium would need to be included in the design?
For a precipitation reaction to be useful in a gravimetric analysis, the product of the reaction must be insoluble. Is Kc1,1 or 1 for a useful precipitation reaction?